1. Technical Field of the Invention
The present invention relates to a method and an apparatus for controlling charging operations for battery, which operations are conducted by a vehicle generator loaded, for example, on a passenger car or a truck.
2. Related Art
As known well, a battery mounted in vehicles need to be adjusted on its operating conditions. Such an example is disclosed in Japanese Patent Laid-Open Publication No. 2003-209935, in which there is disclosed a method for controlling adjustment voltage so that an integrated value of charge/discharge current of an on-vehicle battery will be zeroed, with the aid of the battery-condition (voltage, current and temperature) detecting means, the adjustment voltage controlling means (microcomputer) and the regulator. In this conventional method, adjustment voltage of a vehicle generator is controlled so that an integrated value of charge/discharge current will be zeroed. Liquid loss caused by deterioration in fuel consumption and overcharge has been prevented by performing this control.
Further, as disclosed, for example, in Japanese Patent Laid-Open Publication No. 2005-057853, a method has been known for estimating storage conditions of a battery in a deceleration state and for determining execution of power generation suppression in an acceleration state based on the estimation, with the aid of the driving condition (acceleration, deceleration and low speed) estimating means, the battery condition estimating means and the power generation suppressing means. This conventional method can effect power generation control in response to traveling conditions, based on battery conditions.
The conventional methods mentioned above have been developed without considering engine efficiency or power generation efficiency of a vehicle generator. Therefore, there has been a problem that an operation in a state where these efficiencies are low, has increased useless fuel consumption. In the method disclosed in Japanese Patent Laid-Open No. 2005-057853, the controller for estimating storage conditions of a battery or for determining the execution of power generation suppression is located distanced from the battery. This has raised a problem that the battery is likely to be affected by noise. When this controller has been realized by using an engine control microcomputer, there has been a problem that high engine speed may impose a heavy processing load on the microcomputer in the engine control and that appropriate power generation control may not possibly be performed.